System for preparing liquid fuel through biomass graded oxygen control conversion and working method thereof

Abstract

The invention provides a system for preparing liquid fuel by biomass graded oxygen control conversion and a working method thereof, which are characterized in that forestry and agricultural residues are used as raw materials and respectively enter two production lines of an anaerobic fermentation device and a gasification device, graded oxygen control conversion is used as a core, and green methanol is efficiently produced at low cost. The biogas purification device, the fine desulfurization device, the reforming device, the methanol synthesis device and the rectification device are connected in sequence; the solid-liquid separation device is connected with the fermentation device and the combustible gas purification device; the solid-liquid separation device is connected with the fertilizer preparation device and the biogas residue drying device; the biogas residue drying device, the grinding device, the water carbon slurry gasification device, the synthesis gas purification device and the methanol synthesis device are connected in sequence; the gasification device is connected with the combustible gas purification device, the fermentation device and the water carbon slurry gasification device; the combustible gas purification device is connected with the internal combustion generator set, the reforming device, the fertilizer preparation device and the water carbon slurry gasification device; the waste heat boiler is connected with the steam collecting box; and the steam collecting box is connected with the biogas residue drying and fermenting device and the reforming device.

Description

Technical Field

[0001] The invention relates to a system for producing liquid fuel by graded oxygen-controlled conversion of biomass and a working method thereof. Background Art

[0002] my country is a major agricultural country with a huge output of agricultural and forestry waste, but the utilization rate is low, and there are different problems in biomass power generation and biogas utilization.

[0003] In terms of biomass power generation: (1) The biomass power generation industry has always been heavily dependent on government subsidies. On the one hand, this is due to the high cost of biomass raw materials, and on the other hand, due to the inadequate storage and transportation system, the scale of biomass power generation units is relatively small, resulting in low power generation efficiency and poor benefits. As a result of the overall impact of the gradual withdrawal and reduction of subsidies on the biomass power generation industry, most companies are in a loss-making state.

[0004] (2) Currently, the direction of material energy utilization is relatively single, lacking high value-added comprehensive utilization. The energy density and unit calorific value of biomass determine the upper limit of its unit mass power generation. When the grid-connected electricity price cannot be increased and the benefits are difficult to cover the costs, it is necessary to transform to the comprehensive utilization of biomass to seek multiple benefits and reduce the cost of power generation.

[0005] In terms of biogas utilization: (1) The resources of the biogas industry mainly come from organic materials such as agricultural waste and livestock and poultry manure, as shown in the Chinese patent application number 202110762737.7, entitled "Method for Comprehensive Utilization of Agricultural and Forestry Waste and Livestock and Poultry Manure Resources". However, in actual operation, due to the high costs of collection, transportation and processing, as well as the low awareness of farmers about biogas technology, a large amount of organic resources have not been effectively utilized.

[0006] (2) Currently, the market development of the biogas industry is relatively lagging behind. Biogas projects have poor economic performance and lack market investment enthusiasm. The application areas and market scale of biogas need to be further expanded. At the same time, the brand building and market promotion of the biogas industry also need to be strengthened to enhance the competitiveness and influence of biogas in the energy market.

[0007] In recent years, to achieve carbon peak and carbon neutrality, my country has been committed to safe carbon reduction and, while ensuring energy security, has vigorously implemented renewable energy substitution and accelerated the construction of a clean, low-carbon, safe, and efficient energy system. However, due to the unstable output of renewable energy sources such as wind and solar power, the problem of "wind and solar power curtailment" has become increasingly prominent, even posing a certain threat to the operation of the power grid. To accommodate the increasing amount of renewable energy, proactive measures are needed.

[0008] The development of green methanol is of great strategic significance. It is not only crucial for energy transition and environmental protection, but also promotes high-quality economic development and enhances international competitiveness. Developing green methanol is not only an inevitable choice for addressing climate change and environmental issues, but also a key measure for promoting high-quality economic development, ensuring energy security, and enhancing international competitiveness. Green methanol is expected to become a core component of the future energy system, providing a strong impetus for global sustainable development.

[0009] It can be seen that converting agricultural and forestry waste into green and low-carbon fuels is of great significance. Summary of the Invention

[0010] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a biomass graded oxygen-controlled conversion system for producing liquid fuel and its working method. Agricultural and forestry waste is used as raw material, classified according to different characteristics, and enters two production lines, anaerobic fermentation and gasification, respectively. With graded oxygen-controlled conversion as the core, green methanol is produced efficiently and at low cost.

[0011] The technical solution adopted by the present invention to solve the above problems is: a biomass graded oxygen-controlled conversion system for producing liquid fuel, including a fermentation device, a solid-liquid separation device, a biogas purification device, a fertilizer making device, a gasification device, a combustible gas purification device, an internal combustion generator set, a waste heat boiler, a fine desulfurization device, a reforming device, a methanol synthesis device and a distillation device; the outlet of the fermentation device is respectively connected to the inlet of the biogas purification device and the solid-liquid separation device; the biogas purification device, the fine desulfurization device, the reforming device, the methanol synthesis device, and the distillation device are connected in sequence; the internal combustion generator set is connected to the waste heat boiler; it is characterized in that: it also includes a biogas residue drying device, a grinding device, a steam header, a water-carbon slurry gasification device and a synthesis gas purification device; the biogas liquid outlet of the solid-liquid separation device is respectively connected to the inlet of the fermentation device and the combustible gas purification device; the solid The sludge outlet of the liquid separation device is connected to the fertilizer making device and the sludge drying device respectively; the outlet of the sludge drying device is connected to the inlet of the grinding device, the outlet of the grinding device is connected to the inlet of the water-carbon slurry gasification device, the outlet of the water-carbon slurry gasification device is connected to the inlet of the synthesis gas purification device, and the outlet of the synthesis gas purification device is connected to the inlet of the methanol synthesis device; the outlet of the gasification device is connected to the inlet of the combustible gas purification device, the fermentation device and the water-carbon slurry gasification device respectively; the gas outlet of the combustible gas purification device is connected to the inlet of the internal combustion generator set and the reforming device respectively, the ash outlet is connected to the inlet of the fertilizer making device, and the tar wastewater outlet is connected to the inlet of the water-carbon slurry gasification device; the steam outlet of the waste heat boiler is connected to the inlet of the steam header; the outlet of the steam header is connected to the inlets of the sludge drying, fermentation and reforming devices respectively.

[0012] In the present invention, a biogas slurry buffer device is provided at the biogas slurry outlet of the solid-liquid separation device.

[0013] The gas outlet of the combustible gas purification device of the present invention is provided with a gas storage device.

[0014] The present invention also includes a flue gas purification device, and the flue gas outlet of the reforming device is connected to the flue gas purification device.

[0015] The present invention further comprises a pre-treatment device, the outlet of which is respectively connected to the inlet of the fermentation device, the gasification device and the fertilizer making device.

[0016] The present invention also includes a water electrolysis device, the oxygen outlet of the water electrolysis device is respectively connected to the inlet of the gasification device and the water-charcoal gasification device, and the hydrogen outlet is connected to the inlet of the methanol synthesis device.

[0017] The oxygen outlet of the water electrolysis device of the present invention is provided with an oxygen storage tank, and the hydrogen outlet is provided with a hydrogen storage tank.

[0018] A method for producing liquid fuel by biomass graded oxygen-controlled conversion is characterized by comprising the following steps: (1) Livestock and poultry manure, straw and other organic waste materials are pre-treated, and the non-degradable organic matter separated out enters the gasification device, and the fertilizer-making raw materials enter the fertilizer-making device; (2) The pre-treated livestock and poultry manure, straw and other organic waste materials are sent to the fermentation device to produce biogas, which is then sent to the biogas purification device. The remainder is passed through the solid-liquid separation device to obtain biogas liquid and biogas residue; (3) The woody raw materials are fed into the gasification device to react with the non-degradable organic matter and oxygen produced by the pretreatment to produce combustible gas and biochar; part of the biochar produced by the gasification device enters the fertilizer making device to produce carbon-based fertilizer, part enters the water-carbon slurry gasification device as a reducing agent, and the other part enters the fermentation device as an intermediate carrier to alleviate the inhibition of ammonia nitrogen; (4) Part of the biogas slurry obtained from the solid-liquid separation device is returned to the fermentation device for adjusting the moisture content of the raw materials, and the other part enters the combustible gas purification device to absorb the acidic gas in the combustible gas through the alkaline properties of the biogas slurry; part of the biogas residue obtained from the solid-liquid separation device enters the fertilizer making device for making organic fertilizer, and the other part enters the biogas residue drying device for drying; (5) The biogas purified by the biogas purification unit enters the fine desulfurization unit, and the desulfurized biogas enters the reforming unit, where it reacts with the water vapor from the steam header to produce synthesis gas mainly including hydrogen, carbon monoxide and carbon dioxide; (6) The low-water content biogas residue dried by the biogas residue drying device is sent to the grinding device for grinding, and then sent to the water-carbon slurry gasification device to react with the tar wastewater, oxygen and biomass carbon of the gasification device to produce synthesis gas with the main components of hydrogen, carbon monoxide and carbon dioxide, which is then purified by the synthesis gas purification device; (7) The synthesis gas obtained by reforming is mixed with the synthesis gas produced by the water carbon slurry gasification unit, hydrogen is added, and the mixture is fed into the methanol synthesis unit for methanol synthesis; (8) The primary methanol produced by the methanol synthesis unit is distilled into a distillation unit to produce qualified green methanol products; (9) The desalted water is introduced into the methanol synthesis unit, and after absorbing heat, steam is generated and enters the steam header; (10) The biomass ash produced by the gasification device is fed into the fertilizer making device, and the tar wastewater produced is fed into the water-carbon slurry gasification device; (11) Part of the combustible gas produced by the gasification device is fed into the internal combustion generator set to generate green electricity, and the other part is used for combustion and heat supply in the reforming device; (12) The flue gas generated by the internal combustion generator is introduced into the waste heat boiler, and the steam generated by the waste heat boiler enters the steam header; (13) The steam in the steam header is introduced into the sludge drying device and the fermentation device to meet the heat needs of the devices.

[0019] Compared with the prior art, the present invention has the following advantages and effects: 1. The present invention uses agricultural and forestry waste as raw materials, classifies them according to different characteristics, and feeds them into two production lines, anaerobic fermentation and gasification, respectively. The products generated in the process are then coupled and gasified by a water-carbon slurry gasification device to form a synthetic gas with stable components. With graded oxygen control as the core, green methanol is produced efficiently and at low cost.

[0020] 2. Internal combustion engines have higher power generation efficiency and can meet green electricity requirements. The waste heat at the back end can also be fully utilized. Steam headers are installed throughout the plant to achieve efficient energy utilization and high system efficiency.

[0021] 3. The combustible gas produced by the gasification device is used for power generation and combustion heating in internal combustion engines, solving the problem of unstable operation of traditional gasification devices and unstable combustible gas composition, which makes it difficult to directly use it for methanol synthesis.

[0022] 4. The reforming unit can reduce the separation steps of methane and carbon dioxide, resulting in higher carbon dioxide utilization and lower equipment investment and operating costs.

[0023] 5. The reforming unit fully utilizes the thermal energy of the gas in the system, reduces its own biogas consumption, improves the utilization rate of green carbon sources, and maximizes the green methanol production capacity; 6. Using tar-containing wastewater as raw material for gasification not only solves the problem of wastewater treatment, but also utilizes the organic matter in it, increases gas production rate and reduces energy consumption.

[0024] 7. The products of the entire system are green methanol and carbon-based organic fertilizers. The production process can be flexibly adjusted according to different market needs to achieve the highest economic benefits, break away from the constraints of a single product, and flexibly adjust product output according to the product market.

[0025] 8. The ash produced by the gasification of agricultural and forestry waste is rich in effective nutrients such as potassium and phosphorus. When used in the fertilizer production system, it can not only supplement the nutrients in the fertilizer, but also adjust the moisture content and improve the efficiency and yield of fertilizer production.

[0026] 9. The hydrogen and oxygen produced by water electrolysis are used in the gasification unit and synthesis unit respectively. Both materials can be fully utilized and the system has a high degree of synergy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0029] The embodiment of the present invention includes a pretreatment device 1, a fermentation device 2, a solid-liquid separation device 3, a biogas purification device 4, a fine desulfurization device 5, a reforming device 6, a methanol synthesis device 7, a distillation device 8, a biogas slurry buffer device 9, a biogas residue drying device 10, a grinding device 11, a fertilizer making device 12, a gasification device 13, a combustible gas purification device 14, a gas storage device 15, an internal combustion generator set 16, a waste heat boiler 17, a steam header 18, a water-carbon slurry gasification device 19, a synthesis gas purification device 20, a flue gas purification device 21, a water electrolysis device 22, an oxygen storage tank 23 and a hydrogen storage tank 24.

[0030] The outlet of the pretreatment device 1 is connected to the inlet of the fermentation device 2, the gasification device 13, and the fertilizer production device 12, respectively. The outlet of the fermentation device 2 is connected to the inlet of the biogas purification device 4 and the solid-liquid separation device 3, respectively. The biogas slurry outlet of the solid-liquid separation device 3 is connected to the inlet of the fermentation device 2 and the combustible gas purification device 14, respectively. A biogas slurry buffer device 9 is provided at the biogas slurry outlet of the solid-liquid separation device 3. The biogas residue outlet of the solid-liquid separation device 3 is connected to the fertilizer production device 12 and the biogas residue drying device 10, respectively. The outlet of the biogas purification device 4 is connected to the inlet of the fine desulfurization device 5, the outlet of the fine desulfurization device 5 is connected to the inlet of the reforming device 6, the outlet of the reforming device 6 is connected to the inlet of the methanol synthesis device 7, and the outlet of the methanol synthesis device 7 is connected to the inlet of the distillation device 8. The outlet of the biogas drying unit 10 is connected to the inlet of the grinding unit 11, which is connected to the inlet of the water-charcoal slurry gasification unit 19. The outlet of the water-charcoal slurry gasification unit 19 is connected to the inlet of the synthesis gas purification unit 20, which is connected to the inlet of the methanol synthesis unit 7. The outlet of the gasification unit 13 is connected to the inlets of the combustible gas purification unit 14, the fermentation unit 2, and the water-charcoal slurry gasification unit 19. The gas outlet of the combustible gas purification unit 14 is connected to the inlets of the internal combustion generator set 16 and the reforming unit 6, respectively. The ash outlet is connected to the inlet of the fertilizer production unit 12, and the tar wastewater outlet is connected to the inlet of the water-charcoal slurry gasification unit 19. The gas outlet of the combustible gas purification unit 14 is equipped with a gas storage device 15. The outlet of the internal combustion generator set 16 is connected to the inlet of the waste heat boiler 17, and the steam outlet of the waste heat boiler 17 is connected to the inlet of the steam header 18. The outlet of steam header 18 is connected to the inlets of digestate drying unit 10, fermentation unit 2, and reformer 6, respectively. The oxygen outlet of electrolytic water unit 22 is connected to the inlets of gasification unit 13 and hydrochar gasification unit 19, respectively. The hydrogen outlet is connected to the inlet of methanol synthesis unit 7. The oxygen outlet of electrolytic water unit 22 is equipped with an oxygen storage tank 23, and the hydrogen outlet is equipped with a hydrogen storage tank 24. The flue gas outlet of reformer 6 is connected to flue gas purification unit 21.

[0031] The fertilizer production unit 12 uses biochar, bioash, biogas residue, soil debris, and rotted straw as raw materials, producing charcoal-based organic fertilizer through aerobic fermentation. The water-charcoal slurry gasification unit 19 uses biochar, ground biogas residue, tar wastewater, and oxygen as raw materials, producing synthesis gas through pure oxygen gasification. The steam header 18 is used to balance the steam supply and achieve efficient energy utilization within the system.

[0032] A method for producing liquid fuel from biomass by graded oxygen-controlled conversion. Agricultural and forestry waste materials are classified according to their characteristics and fed into two production lines, anaerobic fermentation and gasification. The products are then coupled with a water-carbon slurry gasification unit to form a stable syngas. The method specifically includes the following steps: (1) Raw materials suitable for anaerobic fermentation, such as livestock and poultry manure, straw and other organic waste, are first pretreated by the pretreatment device 1. The non-degradable organic matter (such as packaging film, ropes, plastic bags, etc.) separated by the pretreatment device 1 enters the gasification device 13, and the fertilizer-making raw materials such as soil and rotten straw enter the fertilizer making device 12; (2) The pre-treated livestock and poultry manure, straw and other organic waste materials are sent to the fermentation device 2 to generate biogas, which is then sent to the biogas purification device 4. The remainder is passed through the solid-liquid separation device 3 to obtain biogas liquid and biogas residue; (3) The woody raw materials are fed into the gasification device 13 to react with the non-degradable organic matter and oxygen produced by the pretreatment device 1 to produce combustible gas and biochar; part of the biochar produced by the gasification device 13 enters the fertilizer making device 12 to produce carbon-based fertilizer, part enters the water-carbon slurry gasification device 19 as a reducing agent, and the other part enters the fermentation device 2 as an intermediate carrier to slow down the inhibition of ammonia nitrogen and improve the gas production rate; (4) The biogas slurry obtained by the solid-liquid separation device 3 is first stored in the biogas slurry buffer device 9. Part of the biogas slurry in the biogas slurry buffer device 9 is returned to the fermentation device 2 for adjusting the moisture content of the raw materials, and the other part enters the combustible gas purification device 14 to absorb the acidic gas in the combustible gas through the alkaline properties of the biogas slurry; part of the biogas residue obtained by the solid-liquid separation device 3 enters the fertilizer making device 12 for making organic fertilizer, and the other part enters the biogas residue drying device 10 for drying; (5) The biogas purified by the biogas purification device 4 enters the fine desulfurization device 5, and the desulfurized biogas enters the reforming device 6, where it reacts with the water vapor from the steam header 18 to produce synthesis gas mainly including hydrogen, carbon monoxide, and carbon dioxide; (6) The low-water content biogas dried by the biogas drying device 10 is sent to the grinding device 11 for grinding, and then sent to the water-carbon slurry gasification device 19 to react with the tar wastewater generated by the combustible gas purification device 14, the oxygen from the oxygen storage tank 23, and the biomass char produced by the gasification device 13 to produce synthesis gas whose main components are hydrogen, carbon monoxide, and carbon dioxide, and then purified by the synthesis gas purification device 20; (7) The reformed synthesis gas is fully mixed with the synthesis gas produced by the water carbon slurry gasification unit 19 and the hydrogen in the hydrogen storage tank 24, and the H / C ratio is adjusted, and then the mixture enters the methanol synthesis unit 7 for methanol synthesis; (8) The primary methanol produced by the methanol synthesis unit 7 is distilled into a distillation unit 8 to produce qualified green methanol products; (9) The desalted water is introduced into the methanol synthesis unit 7, and after absorbing heat, steam is generated and enters the steam header 18; (10) The combustible gas generated by the gasification device 13 is introduced into the combustible gas purification device 14, the clean combustible gas generated is stored in the gas storage device 15, the biomass ash generated is sent to the fertilizer making device, and the tar wastewater generated is sent to the water-carbon slurry gasification device 19; (11) A portion of the combustible gas stored in the gas storage device 15 is fed into the internal combustion generator set 16 to generate green electricity for powering the entire plant, and the other portion is used for combustion and heating in the reforming device 6. After heating, the flue gas passes through the flue gas purification device 21 and meets the emission standards; (12) The flue gas generated by the internal combustion generator 16 is introduced into the waste heat boiler 17, and the steam generated by the waste heat boiler 17 enters the steam header 18. The generated flue gas passes through the purification device and is discharged in compliance with the emission standards; (13) The oxygen and hydrogen generated by the wind-photovoltaic water splitting device 22 are introduced into the oxygen storage tank 23 and the hydrogen storage tank 24 respectively; the oxygen in the oxygen storage tank 23 is introduced into the gasification device 13 to achieve pure oxygen gasification, and is introduced into the water-carbon slurry gasification device 19 as an oxidant; the hydrogen in the hydrogen storage tank 24 is introduced into the methanol synthesis device 7 to adjust the hydrogen-carbon ratio to meet the requirements of methanol synthesis; (14) The steam in the steam header 18 is introduced into the biogas residue drying device 10 and the fermentation device 2 to meet the heat needs of the devices.

[0033] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. Any equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Those skilled in the art of the technology to which the present invention belongs can make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A biomass graded oxygen-controlled conversion system for producing liquid fuel, comprising a fermentation unit, a solid-liquid separation unit, a biogas purification unit, a fertilizer production unit, a gasification unit, a combustible gas purification unit, an internal combustion generator set, a waste heat boiler, a fine desulfurization unit, a reforming unit, a methanol synthesis unit, and a distillation unit; the outlet of the fermentation unit is respectively connected to the inlet of the biogas purification unit and the solid-liquid separation unit; the biogas purification unit, the fine desulfurization unit, the reforming unit, the methanol synthesis unit, and the distillation unit are connected in sequence; and the internal combustion generator set is connected to the waste heat boiler; characterized in that: It also includes a biogas residue drying device, a grinding device, a steam header, a water-carbon slurry gasification device and a synthesis gas purification device; the biogas liquid outlet of the solid-liquid separation device is respectively connected to the inlet of the fermentation device and the combustible gas purification device; the biogas residue outlet of the solid-liquid separation device is respectively connected to the fertilizer making device and the biogas residue drying device; the outlet of the biogas drying device is connected to the inlet of the grinding device, the outlet of the grinding device is connected to the inlet of the water-carbon slurry gasification device, the outlet of the water-carbon slurry gasification device is connected to the inlet of the synthesis gas purification device, and the outlet of the synthesis gas purification device is connected to the inlet of the methanol synthesis device; the outlet of the gasification device is respectively connected to the inlet of the combustible gas purification device, the fermentation device and the water-carbon slurry gasification device; the gas outlet of the combustible gas purification device is respectively connected to the inlet of the internal combustion generator set and the reforming device, the ash outlet is connected to the inlet of the fertilizer making device, and the tar wastewater outlet is connected to the inlet of the water-carbon slurry gasification device; the steam outlet of the waste heat boiler is connected to the inlet of the steam header; the outlet of the steam header is respectively connected to the inlets of the biogas drying, fermentation and reforming devices.

2. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 1, characterized in that: A biogas slurry buffer device is provided at the biogas slurry outlet of the solid-liquid separation device.

3. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 1, characterized in that: The gas outlet of the combustible gas purification device is provided with a gas storage device.

4. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 1, characterized in that: It also includes a flue gas purification device, and the flue gas outlet of the reforming device is connected to the flue gas purification device.

5. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 1, characterized in that: The invention also comprises a pre-treatment device, the outlet of which is respectively connected to the inlet of the fermentation device, the gasification device and the fertilizer making device.

6. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 1, characterized in that: It also includes a water electrolysis device, the oxygen outlet of the water electrolysis device is connected to the inlet of the gasification device and the water-charcoal gasification device respectively, and the hydrogen outlet is connected to the inlet of the methanol synthesis device.

7. The biomass graded oxygen-controlled conversion system for producing liquid fuel according to claim 6, characterized in that: The oxygen outlet of the water electrolysis device is provided with an oxygen storage tank, and the hydrogen outlet is provided with a hydrogen storage tank.

8. A method for producing liquid fuel from biomass by staged oxygen-controlled conversion according to any one of claims 1 to 7, characterized in that: The steps include: (1) Livestock and poultry manure, straw and other organic waste materials are pre-treated, and the non-degradable organic matter separated out enters the gasification device, and the fertilizer-making raw materials enter the fertilizer-making device; (2) The pre-treated livestock and poultry manure, straw and other organic waste materials are sent to the fermentation device to produce biogas, which is then sent to the biogas purification device. The remainder is passed through the solid-liquid separation device to obtain biogas liquid and biogas residue; (3) The woody raw materials are fed into the gasification device to react with the non-degradable organic matter and oxygen produced by the pretreatment to produce combustible gas and biochar; part of the biochar produced by the gasification device enters the fertilizer making device to produce carbon-based fertilizer, part enters the water-carbon slurry gasification device as a reducing agent, and the other part enters the fermentation device as an intermediate carrier to slow down the ammonia nitrogen inhibition during the fermentation process; (4) Part of the biogas slurry obtained from the solid-liquid separation device is returned to the fermentation device for adjusting the moisture content of the raw materials, and the other part enters the combustible gas purification device to absorb the acidic gas in the combustible gas through the alkaline properties of the biogas slurry; part of the biogas residue obtained from the solid-liquid separation device enters the fertilizer making device for making organic fertilizer, and the other part enters the biogas residue drying device for drying; (5) The biogas purified by the biogas purification unit enters the fine desulfurization unit, and the desulfurized biogas enters the reforming unit, where it reacts with the water vapor from the steam header to produce synthesis gas mainly including hydrogen, carbon monoxide and carbon dioxide; (6) The low-water content biogas residue dried by the biogas residue drying device is sent to the grinding device for grinding, and then sent to the water-carbon slurry gasification device to react with the tar wastewater, oxygen and biomass carbon of the gasification device to produce synthesis gas with the main components of hydrogen, carbon monoxide and carbon dioxide, which is then purified by the synthesis gas purification device; (7) The synthesis gas obtained by reforming is mixed with the synthesis gas produced by the water carbon slurry gasification unit, hydrogen is added, and the mixture is fed into the methanol synthesis unit for methanol synthesis; (8) The primary methanol produced by the methanol synthesis unit is distilled into a distillation unit to produce qualified green methanol products; (9) The desalted water is introduced into the methanol synthesis unit, and after absorbing heat, steam is generated and enters the steam header; (10) The biomass ash produced by the gasification device is fed into the fertilizer making device, and the tar wastewater produced is fed into the water-carbon slurry gasification device; (11) Part of the combustible gas produced by the gasification device is fed into the internal combustion generator set to generate green electricity, and the other part is used for combustion and heat supply in the reforming device; (12) The flue gas generated by the internal combustion generator is introduced into the waste heat boiler, and the steam generated by the waste heat boiler enters the steam header; (13) The steam in the steam header is introduced into the sludge drying device and the fermentation device to meet the heat needs of the devices.

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